For example, rudders or rudder segments are provided in wing and control surfaces for control purposes. Additional flaps are also used for adjusting the profile to aerodynamic conditions, for example in the starting phase, during cruise flight, or even in the landing phase. Both the use of rudder elements and the use of additional flaps serves to change the aerodynamically active profile, i.e., so as to be able to adjust the respective wing and control surfaces to various situations. For example, DE 103 17 258 B4 describes an adjustment mechanism for a variable-shape wing. However, it has been shown that there exists an added demand for further changes in the contour of the wing profile.
Therefore, the object of the present embodiment is to provide an aerodynamic structure that can be adjusted and changed in a variety of ways with regard to the wing profile.
This object is achieved by an aerodynamic structure for a wing or rudder arrangement of an aircraft, an aircraft, a method for adjusting the outer contour of an aerodynamic structure for a wing or rudder arrangement, and the use of an aerodynamic structure in an aircraft according to one of the independent claims. Exemplary embodiments are described in the claims.
According to an embodiment, an aerodynamic structure for a wing or rudder arrangement of an aircraft is provided. The aerodynamic structure comprises a support structure and an outer skin. The support structure comprises an adaptive surface support structure in the longitudinal direction, which extends in the longitudinal direction from a root area to an outer end area, and is formed by a support surface, which exhibits an adjustable periodic profiling that runs in a transverse direction, in which first and second flange areas are alternatingly formed, and joined together by web areas running in the direction of a profile height. Alternatingly aligned open profile segments running in the longitudinal direction are here formed. In the area of the open profile segments, the support structure comprises several connecting segments running in the transverse direction, which join together two adjacent first or second flange areas. At least a portion of the connecting segments are designed as adjustable-length connecting segments, so that the distance between the adjacent first or second flange areas can be adjusted. The outer skin is attached to the support surface. An outer contour of the aerodynamic structure can be changed at least in the transverse direction by adjusting the distance between the adjacent first or second flange areas.
Provided in this way on the one hand is a supporting structure, for example for a wing or rudder arrangement, but which on the other hand can already be changed in terms of this contour relative to the transverse direction of the wing. In other words, the support structure itself is already designed to be changeable, so as to provide an outer contour of the aerodynamic structure that is as variably adjustable as possible.
Because the outer contour is adjustable, the aerodynamic drag can be reduced, for example in the case of rudders or also wings. The aerodynamic performance of the wing or rudder can be improved at the same time, for example because slits for modifying the aerodynamically effective contour in the case of additional flaps, etc., are not required given the changing shape of the support structure. Another advantage to the absent slit is a reduction in noise and decrease in the electromagnetic signature (radar signature) of an aircraft.
The terms “transverse direction” and “longitudinal direction” relate to a wing or rudder arrangement running transverse to the flight direction. For example, the longitudinal direction of an oblong wing as viewed in the attachment direction runs transverse to the flight direction. The transverse direction then runs in the flight direction, for example.
Given wing or rudder arrangements inclined relative to the flight direction, the transverse direction runs inclined in relation to the longitudinal axis of the wing, for example.
Given a wing or rudder arrangement attached at one end to a support structure, e.g., a fuselage structure, the longitudinal direction can also be referred to as the attachment direction, overhang direction or primary direction. The transverse direction then runs transverse to the attachment direction, and can also be referred to as the secondary direction.
In the case of a wing, the root area is the wing root, and the outer end area is the outer wing end.
The term “periodic profiling” refers to a repeating sequence of flanges and webs, as well as to the alternatingly aligned, open profile segments. The profiling can here vary in its specific dimensions, e.g., increase or decrease with the degree of profiling. For example, the profiling can exhibit an increasing or decreasing periodicity or an increasing or decreasing amplitude.
The periodic profiling can also be referred to as a wavelike profile, wherein waves are also understood as trapezoidal structures, or trapezoidal waves.
The web areas run in the direction of the profile height, and the flange areas run on the two outer sides of the profiling, e.g., in the upper and lower areas of the profiling for a wing.
In an example, the adjustable-length connecting segments are provided as actuating drives, actuating elements, guide elements or actuators.
The support structure is formed by the surface supporting structure and the connecting segments. As a consequence, the support structure forms a stable inner structure of the aerodynamic structure, for example of a wing or a rudder.
“Aerodynamic structure” refers to the constituent of a wing or rudder arrangement that produces the aerodynamic effect during aircraft operation, e.g., generates an upward or downward force on a wing, or generates a torque on a rudder to change the direction. The aerodynamic structure can also be referred to as a wing or rudder structure. The term “aerodynamic structure” is used in conjunction with the present embodiment to denote the constituents shared in common by a wing and rudder arrangement. For example, wing and rudder arrangements exhibit an outer surface exposed to the air flow, which is also referred to as the outer skin. This surface produces the desired aerodynamic effect, e.g., due to its contour or shape, i.e., because of its cross section exposed to the air flow. Wing and rudder arrangements also exhibit a support structure, so as to hold the surface exposed to the air flow, and introduce the generated forces into the structure of the aircraft.
A portion of the connecting segments are designed as fixed connecting elements, for example.
For example, the aircraft is an airplane; e.g., the aerodynamic structure is a wing surface of a supporting framework of a control surface of a tail unit. The “wing surface” is also referred to as a wing arrangement. In another example, the wing surface is an (essential) constituent of the wing arrangement. The “control surface” is also referred to as a rudder arrangement. In another example, the control surface is an (essential) constituent of the rudder arrangement. The adaptive framework segments provide a variably shaped aerodynamic structure.
The surface support structure comprises a longitudinal beam. The periodic profiling together with the connecting segments forms a transverse rib, or several transverse ribs sequentially provided in the longitudinal direction.
An example provides that the periodic profiling be designed as a trapezoidal profiling and/or a wavelike profiling. This provides an easily to manufacture surface support structure, which is adjustable on the one hand, and exhibits enough stability for introducing the forces on the other. The profiling can also comprise trapezoidal and wavelike segments. In a wavelike profiling, the valley and peak segments of the wave structure form the flange areas, and the areas of the wave structure lying in between form the web areas. The profile can also exhibit a polygonal periodic profiling.
In an example, the web areas and flange areas are interconnected in a longitudinal direction. The profiling can be adjusted in the transverse direction in such a way that a width of the open profile segments can be varied by means of the adjustable connecting segments.
An example provides that a segment open to the top or bottom be divided with an intermediate web, and that fixed connections or adjustable guide elements be provided between the lateral walls, i.e., the webs and the intermediate web.
An example provides that the connecting areas between the web areas and flange areas exhibit a flexibility, so as to change an angle between the web areas and flange areas. The variability of the angle is tailored to the possible change in length of the adjustable connecting segment, for example. An example provides that the web areas be deformable to a certain extent.
In an example, at least one open profile segment is designed as a spar, which extends in the longitudinal direction from a root area to an outer end area. Providing a spar offers additional stability, so that the surface support structure is exposed to other loads in the other areas, as a result of which these areas make do with less material, thereby additionally economizing on weight. In an example, the spar is integrated into the surface support structure.
In an example, the surface support structure is connected to the spar in a central area of the surface support structure in such a way that adaptive areas of the surface support structure transverse to the longitudinal direction of the spar are formed on both sides of the spar, e.g., that a front and rear adaptive area are formed.
In an example, the outer skin can be shaped, and is attached to the surface support structure at least partially via hold points by means of retaining elements. At least a portion of the retaining elements is designed as adaptive mounts, with which the location of the hold points in relation to the surface support structure can be varied.
The retaining elements are also referred to as secondary connecting segments or secondary connecting elements, and the adaptive mounts as secondary, adjustable-length connecting elements. The connecting elements of the surface support structure can be referred to as primary connecting elements, i.e., primary fixed-length connecting elements, and primary adjustable-length connecting elements. For example, the front edge and lateral surfaces of the outer skin are attached to the flange areas by means of retaining elements. On the rear edge, the outer skin can be attached directly to the end areas of the surface support structure.
For example, the hold points are designed as a secondary wing assembly, e.g., as a girder grid with support brackets running longitudinally to the profiling of the surface support structure. The surface support structure together with the connecting segments comprise the primary wing assembly. An example provides that the adaptive mounts be adjustable-length hold members, with which the distance between the hold points and surface support structure can be adjusted. In another example, the adaptive mounts are alternatively or additionally designed as pivoting arms, whose pivoting degree relative to the surface support structure can be adjusted. In an example, the outer skin is a single piece. For example, the outer skin is flexible transverse to the surface. In another example, the outer skin is designed so that it can expand in the direction of the surface. For example, an expandable material or expandable structure is provided for the outer skin, e.g., honeycombs and hybrid composites filled with elastic plastics.
An example provides that changing the profile be controlled in such a way as to prevent any change in length from arising in the surface of the outer skin.
According to the embodiment an aircraft is also provided, which exhibits a fuselage structure, a wing assembly with at least one wing surface, and a tail unit with at least one control surface. The wing assembly and tail unit are held on the fuselage structure. At least one wing surface and/or one control surface is designed with an aerodynamic structure according to one of the preceding examples.
For example, the wing assembly encompasses one or more wings. For example, the tail unit encompasses an elevator, a fin and/or an aileron.
Also provided are combinations thereof, e.g., tailerons or V-tail units. Tailerons are elevators provided on the tail of an airplane, and in which the actual functions of an aileron are enhanced or even entirely replaced by independently actuating the two rudder halves.
According to the embodiment also a method for adjusting an outer contour of an aerodynamic structure for a wing or rudder arrangement is provided. The method comprises the following steps: A) Providing an aerodynamic structure for a wing or rudder arrangement of an aircraft. The aerodynamic structure exhibits a support structure and an outer skin, wherein the support structure exhibits an adaptive surface support structure in the longitudinal direction, which extends in a longitudinal direction from a root area to an outer end area, and is formed by a supporting surface, which exhibits an adjustable periodic profiling that runs in a transverse direction, in which first and second flange areas are alternatingly formed, and joined together by web areas running in the direction of a profile height, wherein alternatingly aligned open profile segments running in the longitudinal direction are here formed. In the area of the open profile segments, the support structure exhibits several connecting segments running in the transverse direction, which join together two adjacent first or second flange areas. At least a portion of the connecting segments are designed as adjustable-length connecting segments. The outer skin is attached to the supporting surface. B) Adjusting the adjustable-length connecting segments. C) Changing the outer contour of the aerodynamic structure at least in the transverse direction.
The embodiment also provides for the use of an aerodynamic structure according to one of the preceding examples in an aircraft.
An aspect of the embodiment provides that an aerodynamic structure, for example a wing, be designed with an adjustable support structure. In a bearing element profiled in the transverse direction that serves as the inner support structure, the support structure is adjusted by inserting actuators into the profiling with which the profiling can be changed. To this end, the profiling is given a periodic design, so that the distance between lateral web segments can be changed in the open profile segments. Since the outer skin is attached to the profiling, changing the inner support structure also causes a change to the outer contour. In addition, the aerodynamic structure can be altered by changing the length of the actuators between the support structure and outer skin.
It is noted that the features in the exemplary embodiments and aspects of the devices also apply to embodiments of the method and use of the device and vice versa. In addition, those features can be freely combined with each other even if doing so is not explicitly mentioned, wherein synergistic effects can arise that go beyond the sum total of different features.